Method of forming a glass article and the glass article formed thereby

ABSTRACT

A method of forming a glass article includes providing a first glass sheet. The first glass sheet is heated to a temperature suitable for shaping. The first glass sheet is deposited on a first bending tool. An edge portion of the first glass sheet is disposed over a shaping surface of the first bending tool. The shaping surface of the first bending tool is configured to provide in the first glass sheet a compression area and a tension area. The first glass sheet is shaped on the first bending tool and the compression area is formed in the edge portion of the first glass sheet. The compression area includes a first portion and a second portion. The first portion has a width which is greater than a width of a second portion.

BACKGROUND OF THE INVENTION

The invention also relates to a method of forming a glass article. Theinvention also relates to the glass article that is formed by themethod.

Various processes are known for shaping or bending a sheet of glass.Typically, a glass sheet is heated to a temperature where the glasssheet is deformable and then the bending process is carried out. Incertain bending processes, the heated glass sheet is supported on a ringmember and allowed to sag under the influence of gravity, with orwithout the assistance of an additional pressing force. Another knownglass sheet bending process is a press bending process whereby a glasssheet (or a nested pair) is bent between a pair of complementary shapingmembers, usually in a spaced vertical relationship.

After being shaped, electronic equipment and/or other devices may bedisposed on the glass sheet. Typically, electricity must be reliablysupplied to the equipment and devices to power the aforementioned items.Wire assemblies are often used to supply the electricity. However,attaching certain portions of the wire assembly to the glass sheet cancause damage to the glass sheet. If the glass sheet is included in awindshield, the damage can lead to a windshield failure or failure ofthe items disposed thereon. Thus, it would be desirable to provide aglass sheet that may be used in a windshield or another glazing that isnot damaged by attaching a wire assembly or another member utilized tosupply power thereto.

SUMMARY OF THE INVENTION

Embodiments of a method of forming a glass article are provided. In anembodiment, the method comprises providing a first glass sheet. Thefirst glass sheet is heated to a temperature suitable for shaping. Thefirst glass sheet is deposited on a first bending tool. An edge portionof the first glass sheet is disposed over a shaping surface of the firstbending tool. The shaping surface of the first bending tool isconfigured to provide in the first glass sheet a compression area and atension area. The first glass sheet is shaped on the first bending tooland the compression area is formed in the edge portion 18 of the firstglass sheet. The compression area comprises a first portion and a secondportion. The first portion has a width which is greater than a width ofa second portion.

Preferably, the tension area is formed in a second portion of the firstglass sheet which is located inward of the edge portion of the firstglass sheet and a transition is formed in a third portion of the firstglass sheet.

Preferably, the compression area surrounds the tension area and atransition formed in the first glass sheet.

Preferably, the method further comprises positioning an electricalcomponent over the first portion of the compression area and providingthe electrical component in mechanical communication with the firstglass sheet via a soldering process.

Preferably, the shaping surface of the first bending tool is configuredto provide in the first glass sheet a transition between the compressionarea and the tension area.

Preferably, the edge portion of the first glass sheet comprises a firstedge portion and a second edge portion, the first portion of thecompression area being formed in the first edge portion and the secondportion of the compression area being formed in the second edge portion.

Preferably, the first edge portion is a trailing edge portion and thesecond edge portion is a leading edge portion.

Preferably, the edge portion of the first glass sheet comprises a firstedge portion, the first portion and the second portion of thecompression area each being formed in the first edge portion.

Preferably, the method further comprises laminating the first glasssheet to a second glass sheet.

Preferably, the compression area is formed by cooling the edge portionof the first glass sheet via contact between the edge portion of thefirst glass sheet and the first bending tool.

Preferably, the method further comprises cooling the edge portion of thefirst glass sheet via contact between the edge portion of the firstglass sheet and a second bending tool.

Preferably, the method further comprises forming a transition in aportion of the first glass sheet which is adjacent the edge portion ofthe first glass sheet, the portion of the first glass sheet beingdisposed over but not in contact with the first bending tool.

Preferably, the method further comprises forming a transition in aportion of the first glass sheet which is adjacent the edge portion ofthe first glass sheet, wherein a space separates the portion of thefirst glass sheet and the first bending tool.

Preferably, the shaping surface of the first bending tool comprises afirst segment and an inner end of the first portion of the compressionarea is adjacent an inner edge of the first segment such that atransition is formed in a portion of the first glass sheet which islocated inward of the inner edge of the first segment.

Preferably, the inner end of the first portion of the compression areais aligned with the inner edge of the first segment.

Preferably, the shaping surface of the first bending tool comprises afirst segment, the first segment including a first width which isgreater than the width of the first portion of the compression area.

Preferably, the width of the first portion of the compression area isgreater than a width of a portion of a transition formed in the firstglass sheet inward of the first portion of the compression area.

Preferably, the shaping surface of the first bending tool comprises afirst segment, the first segment including an upper surface configuredto support the first glass sheet.

Preferably, the first portion of the compression area being formed overthe upper surface.

Preferably, the upper surface is formed in a unitary manner.

Preferably, the first segment also comprises an outer portion and aninner portion, the outer portion extending from an outer edge to theinner portion and the inner portion extending from the outer portion toan inner edge.

Preferably, the first portion of the compression area is formed over theouter portion and a transition is formed in the first glass sheet overthe inner portion.

Preferably, the inner portion gradually reduces in thickness toward theinner edge.

Preferably, the first segment also includes an inner edge, the firstportion of the compression area being formed over the upper surface andan inner end of the first portion of the compression area being formedover the inner edge of the first segment.

Also, embodiments of a glass article are provided. In an embodiment, theglass article comprises a first glass sheet. The first glass sheetcomprises a compression area and a tension area formed in the firstglass sheet. The compression area exhibits a compressive area stress of20-100 MPa and is formed in an edge portion of the first glass sheet.The compression area comprises a first portion and a second portion. Thefirst portion has a width which is greater than a width of a secondportion.

Preferably, the tension area is formed in a second portion of the firstglass sheet, the second portion of the first glass sheet is locatedinward of the edge portion of the first glass sheet, and a transition isformed in the first glass sheet in a third portion of the first glasssheet.

Preferably, the glass article further comprises a first terminalconnector positioned over the first portion of the compression area andin mechanical communication with the first glass sheet.

Preferably, a transition in the first glass sheet is inward of a firstterminal connector in mechanical communication with the first glasssheet.

Preferably, the glass article further comprises a second terminalconnector which is in a spaced apart relationship with the firstterminal connector.

Preferably, the first terminal connector is in a spaced apart andparallel relationship with a portion of a peripheral edge of the firstglass sheet.

Preferably, the edge portion of the first glass sheet comprises a firstedge portion and a second edge portion, the first portion of thecompression area being formed in the first edge portion and the secondportion of the compression area being formed in the second edge portion.

Preferably, the first portion of the compression area is in a spacedapart relationship with the second portion of the compression area.

Preferably, the first portion of the compression area is adjacent thesecond portion of the compression area.

Preferably, the first portion of the compression area extends from aperipheral edge of the first glass sheet to the second portion of thecompression area.

Preferably, a transition from the first portion of the compression areato the second portion of the compression area is sharply defined.

Preferably, a transition in the first glass sheet comprises a curvedportion.

Preferably, a transition in the first glass sheet comprises a linearportion.

Preferably, a transition in the first glass sheet comprises a firstportion, the first portion extending from the edge portion of the firstglass sheet, a second portion provided in a parallel relationship withthe first portion, the second portion extending from the edge portion ofthe first glass sheet, and a third portion connecting the first portionto the second portion.

Preferably, the third portion is provided in a perpendicularrelationship with the first portion and the second portion.

Preferably, the edge portion of the first glass sheet comprises a firstedge portion, the first portion of the compression area and the secondportion of the compression area being formed in the first edge portion.

Preferably, the width of the first portion gradually increases in adirection toward a first end of the first portion.

Preferably, a transition in the first glass sheet exhibits an areastress of 0 MPa and the tension area exhibits a tensile area stress ofless than 8 MPa.

Preferably, the glass article further comprises a polymeric interlayerprovided between the first glass sheet and a second glass sheet.

Preferably, the first glass sheet is shaped.

Preferably, the shaped first glass sheet is flat or bent.

Preferably, in the first glass sheet a transition is located between acompression area and a tension area.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The above, as well as other advantages of the present invention willbecome readily apparent to those skilled in the art from the followingdetailed description when considered in the light of the accompanyingdrawings in which:

FIG. 1 is a schematic representation of an embodiment of a glass shapingline in accordance with the invention;

FIG. 2 is a perspective view of an embodiment of a portion of a firstbending tool suitable for use the glass shaping line of FIG. 1 ;

FIG. 3 is a sectional view through a portion of an embodiment of thefirst bending tool and a portion of an embodiment of a second bendingtool;

FIG. 3A is a sectional view through a portion of another embodiment ofthe first bending tool and a portion of an embodiment of a secondbending tool;

FIG. 4 is a top view of another embodiment of a portion of a firstbending tool suitable for use the glass shaping line of FIG. 1 ;

FIG. 5 is a front view of an embodiment of glass article in accordancewith the invention;

FIG. 5A is an enlarged view of a portion of the glass article of FIG. 5;

FIG. 6 is a sectional view of the portion of the glass article of FIG.5A taken along line 6-6;

FIG. 7 is a front view of another embodiment of glass article inaccordance with the invention;

FIG. 8 is a front view of yet another embodiment of glass article inaccordance with the invention; and

FIG. 9 is a front view of a further embodiment of glass article inaccordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

It is to be understood that the invention may assume various alternativeorientations and step sequences, except where expressly specified to thecontrary. It is also to be understood that the specific articles,assemblies and features illustrated in the attached drawings, anddescribed in the following specification are simply exemplaryembodiments of the inventive concepts. Hence, specific dimensions,directions, or other physical characteristics relating to theembodiments disclosed are not to be considered as limiting, unlessexpressly stated otherwise. Also, although they may not be, likeelements in various embodiments described herein may be commonlyreferred to with like reference numerals within this section of theapplication.

Embodiments of a method of forming a glass article and the glass articleformed by the method are described herein and with reference to FIGS.1-9 .

The method comprises providing a first glass sheet 10. In an embodiment,the first glass sheet 10 has a soda-lime-silicate composition. A typicalsoda-lime-silicate glass composition is (by weight), SiO₂ 69-74%; Al₂O₃0-3%; Na₂O 10-16%; K₂O 0-5%; MgO 0-6%; CaO 5-14%; SO₃ 0-2% and Fe₂O₃0.005-2%. In certain embodiments, the first glass sheet 10 may be of alow iron composition. In these embodiments, the first glass sheet 10 maycomprise less than 200 parts per million Fe₂O₃. The glass compositionmay also contain other additives, for example, refining aids, whichwould normally be present in an amount of up to 2%. In otherembodiments, the first glass sheet 10 may be of another composition. Forexample, the first glass sheet 10 may be of a borosilicate compositionor an aluminosilicate composition. An example of a glass of analuminosilicate composition suitable for use as the first glass sheet 10is Gorilla® Glass, which is manufactured and sold by CorningIncorporated.

The first glass sheet 10 may have a thickness between 0.5-25 millimeters(mm), typically a thickness between 0.5-8 mm. When the first glass sheet10 is sufficiently thin, it may be desirable that the first glass sheet10 is chemically strengthened. An example of a suitable chemicallystrengthened aluminosilicate glass is the aforementioned Gorilla® Glass.A preferred chemically strengthened glass having a soda-lime-silicateglass composition is Glanova™, which is manufactured and sold by NipponSheet Glass Co. Ltd. Other chemically strengthened glasses are alsosuitable for use as the first glass sheet 10.

The shape of the first glass sheet 10 may vary between embodiments. Incertain embodiments, the first glass sheet 10 may have a generallyrectangular shape. The first glass sheet 10 has a first major surface 14and a second major surface 16. The second major surface 16 opposes thefirst major surface 14. Also, the first glass sheet 10 comprises an edgeportion 18. The edge portion 18 can be flat or curved. The edge portionincludes one or more portions of the first glass sheet 10 disposedbetween the first major surface 14 and the second major surface 16. Thefirst glass sheet 10 also comprises a peripheral edge 20. In anembodiment, the peripheral edge 20 is a minor surface of the first glasssheet 10 that connects the first major surface 14 to the second majorsurface 16.

The edge portion 18 may comprise one or more portions. In an embodiment,the edge portion 18 may comprise a first edge portion and a second edgeportion. The first edge portion may refer to a leading edge portion or atrailing edge portion of the first glass sheet 10. Alternatively, thefirst edge portion may refer to a first pillar edge portion or a secondpillar edge portion of the first glass sheet 10. The second edge portionmay also refer to the leading edge portion or the trailing edge portion.For example, when the first edge portion refers to leading edge portion,the second edge portion may refer to the trailing edge portion.Alternatively, the second edge portion may refer to the first pillaredge portion or the second pillar edge portion. Thus, as an example,when the first edge portion refers to leading edge portion or thetrailing edge portion, the second edge portion may refer to the firstpillar edge portion or the second pillar edge portion. In theembodiments described above, the leading edge portion and the trailingedge portion are disposed on opposite ends of the first glass sheet 10.The first pillar edge portion and second pillar edge portion aredisposed on opposite sides of the first glass sheet 10. In someembodiments, the edge portion 18 of the first glass sheet 10 maycomprise the first edge portion, the second edge portion, a third edgeportion, and a fourth edge portion.

Preferably, the first glass sheet 10 is shaped utilizing one or moretools 32, 96. After shaping, the first glass sheet 10 may be generallyflat or bent. An example of a suitable glass shaping process will bedescribed with reference to FIG. 1 , which illustrates an embodiment ofa glass shaping line 22. In certain embodiments, the glass shaping line22 is of the press bending variety. In other embodiments (not depicted),the glass shaping line may be of the gravity bending variety.

The glass shaping line 22 may include a preheating furnace 24. Thepreheating furnace 24 serves to heat the first glass sheet 10 beforeshaping of the first glass sheet 10 occurs. In the preheating furnace24, the first glass sheet 10 is heated to a temperature suitable forshaping. For example, the first glass sheet 10 may be heated to atemperature of 590-670° C. Accordingly, the first glass sheet 10 mayalso be referred to as a heated glass sheet.

The first glass sheet 10 may be transported through the preheatingfurnace 24 on rollers 26. When provided, the rollers 26 are spacedapart. The spacing of the rollers 26 is reduced near the exit of thepreheating furnace 24, since the first glass sheet 10 in the heatedstate is deformable and therefore requires greater support.

The preheating furnace 24 is followed by a bending station 28. Thebending station 28 may include a stopping device 30. The stopping device30 is used to prevent the first glass sheet 10 from moving beyond thebending station 28 before it is deposited on a first bending tool 32.The bending station 28 may also include a plurality of moveable rollers34. However, it should be appreciated that the bending station 28 maycomprise an alternative mechanism for transporting and transferring thefirst glass sheet 10. In the embodiments illustrated, the first glasssheet 10 is transported onto the moveable rollers 34 from the rollers 26in the preheating furnace 24 as soon as the first glass sheet 10 exitsthe preheating furnace 24. After being transported onto the plurality ofmoveable rollers 34, the first glass sheet 10 continues to move in thedirection of glass travel. The moveable rollers 34 may be movedvertically to facilitate depositing and positioning the first glasssheet 10 on the first bending tool 32. After the first glass sheet 10has been shaped, the moveable rollers 34 may be moved in an upwarddirection to lift the shaped glass sheet off of the bending tool 32. Anair lift assembly (not depicted) may be provided at the bending station.When provided, the air lift assembly helps to eliminate opticaldistortion caused by roller marks by facilitating positioning of a glasssheet on the first bending tool and transferring the glass sheet fromthe moveable rollers to the bending tool. Once the first glass sheet 10has been deposited on the first bending tool 32 and prior to beingshaped, the position of the first glass sheet 10 may be adjustedutilizing one or more positioning assemblies (not depicted).

In some embodiments, the first glass sheet 10 is shaped on the firstbending tool 32. The first bending tool 32 may be a female tool. In anembodiment, the first bending tool 32 is a ring-type mold. Asillustrated best in FIG. 2 , the first bending tool 32 may have agenerally rectangular outline or periphery configured to support a glasssheet also having a rectangular outline.

The first bending tool 32 comprises a shaping surface 36, in particulara concave shaping surface. As used herein, the shaping surface 36 of thefirst bending tool 32 refers to the portion of the first bending tool 32that the glass sheet is deposited on and any position, configuration, ororientation thereof. More particularly, the first bending tool 32comprises an upper shaping surface 36 for shaping and supporting theglass sheet thereon. After the first glass sheet 10 has been received bythe first bending tool 32, the first glass sheet 10 is supported on theshaping surface 36. The shaping surface 36 may be configured to supportthe first glass sheet 10 in a peripheral region thereof. The firstbending tool 32 may also support a stack of glass sheets thereon, inparticular a nested pair separated by a suitable parting agent such ascalcium carbonate.

After the first glass sheet 10 is deposited on the first bending tool32, the edge portion 18 of the first glass sheet 10 is disposed over theshaping surface 36 of the first bending tool 32. In this position, theedge portion 18 of the first glass sheet 10 is in contact with theshaping surface 36 of the first bending tool 32. As used herein, theedge portion 18 of the first glass sheet 10 refers to the portion(s) ofthe first glass sheet 10 which are disposed over and in contact with theshaping surface 36 of the first bending tool 32.

During contact with the shaping tool(s) 32, 96, a temperaturedistribution is established in the first glass sheet 10. As the firstglass sheet 10 subsequently cools, stresses are generated in the sheetmaterial as a result of these temperature differentials. One componentof this stress field may be referred to as “area” or “regional” stress.The area stress may be viewed or measured using techniques known to aperson skilled in the art using a suitable polariscope or measured with,for example, a Sharples S-69 Edge Stress Meter in reflection, which isavailable from Sharples Stress Engineers Ltd, Unit 29 Old MillIndustrial Estate, School Lane, Bamber Bridge, Preston, Lancashire, PR56SY UK (http://www.sharplessstress.com/edgestress.htm). Area stressmeasurements may also be made in transmission if no obscuration band (orthe like) is on one or more of the glass surfaces being measured.

As the edge portion 18 of the first glass sheet 10 is in contact withthe shaping surface 36 of the first bending tool 32 and, preferably, theshaping surface 98 of a second bending tool 96, the edge portion willcool faster than other portions 38, 40 of the first glass sheet 10,which are not in contact with the shaping surface 36 during shaping.Cooling the edge portion 18 of the first glass sheet 10 faster thanother portions 38, 40 of the first glass sheet 10 allows a compressionarea 42 to be formed in the edge portion 18. After shaping, the firstglass sheet 10 also includes a tension area 44 and a transition 46 inthe first glass sheet.

The compression area 42, tension area 44, and transition 46 can each becharacterized by forces acting on the first glass sheet 10. In thecompression area 42, compressive area stress is formed. In someembodiments, a compressive area stress of 20-100 MPa is exhibited in thecompression area 42. Preferably, a compressive area stress of 20-50 MPais exhibited in the compression area 42. Due to conservation of energy,a balancing region of tensile area stress is formed in the tension area44. Preferably, a tensile area stress of less than 8 MPa is exhibited inthe tension area 44. The transition is formed between the compressionarea 42 and the tension area 44. The transition is a line of zero areastress formed in the first glass sheet and between the compression area42 and the tension area 44. In the transition 46, an area stress equalto 0 MPa is exhibited.

The compression area 42 is formed in the edge portion 18 of the firstglass sheet 10. The compression area 42 corresponds to the portions ofthe shaping surface 36 that the first glass sheet 10 is disposed overand in contact with. Thus, the shaping surface 36 of the first bendingtool 32 can utilized to define the position, size, and shape of one ormore portions 48, 50 of the compression area 42.

The transition 46 is formed in another portion 38 of the first glasssheet 10. This portion 38 of the first glass sheet 10 is adjacent theedge portion 18 of the first glass sheet 10 and is disposed over but notin contact with the first bending tool 32 during shaping. Hence, theconfiguration of the shaping surface 36 of the first bending tool 32 canbe utilized to provide the transition 46 in a predetermined location. Aswill be described in more detail below, an outer perimeter 52 of shapingsurface 36 of the first bending tool 32 is not covered by the firstglass sheet 10.

Preferably, the compression area 42 comprises a first portion 48 and asecond portion 50. The first portion 48 has a width W₁ which is greaterthan a width W₂ of a second portion 50. The width W₁ of the firstportion 48 is measured normal to the peripheral edge 20 of the firstglass sheet 10 inward toward the portion of transition 46 adjacent theinner end of the first portion 48. Similarly, the width W₂ of the secondportion 50 is measured normal to the peripheral edge of the first glasssheet 10 inward toward the portion of transition 34 adjacent the innerend of the second portion 50. As used to describe measuring the width W₁of the first portion 48 and the width W₂ of the second portion 50,normal means relative to a tangent on the peripheral edge of the firstglass sheet. Additionally, it is preferred that the width W₁ of thefirst portion 48 is greater than a width of the portion of thetransition 46 adjacent the inner end of the first portion 48.

The width W₁ of the first portion 48 may be 5 mm of more. In someembodiments, the width W₁ of the first portion 48 is 12.5 mm or more. Inone such embodiment, the width W₁ of the first portion 48 is 12.5-100mm. In another embodiment, the width W₁ of the first portion 48 is12.5-75 mm. In these embodiments, it may be preferred that the width ofthe first portion 48 is 12.5-50 mm. More preferably, the width W₁ of thefirst portion 48 may be 12.5-25.4 mm. The width W₂ of the second portion50 may be 2.5 mm of more. In an embodiment, the width W₂ of the secondportion 50 is 5 mm or more. In other embodiments, the width W₂ of thesecond portion 50 is 12.5 mm or more. In one such embodiment, the widthW₂ of the second portion 50 is 12.5-100 mm. In another embodiment, thewidth W₂ of the second portion 50 is 12.5-75 mm. In these embodiments,it may be preferred that the width W₂ of the second portion 50 is12.5-50 mm. More preferably, the width W₂ of the second portion 50 is12.5-25.4 mm. Even more preferably, the width W₂ of the second portion50 is 12.5-20 mm.

The shaping surface 36 is utilized to form the first portion 48 and thesecond portion 50. As the first portion 48 has a width W₁ which isgreater than a width W₂ of the second portion 50, the shaping surface 36of the first bending tool 32 can be utilized to define the width W₁ ofthe first portion 48 and the width W₂ of the second portion 50. Also,the shaping surface 36 of the first bending tool 32 can be utilized toprovide the compression area 42 or a portion thereof with a desiredshape. For example, the shaping surface 36 of the first bending tool 32can be utilized to provide the compression area 42 with a generallyrectangular outline or another outline of a regular shape.Alternatively, the shaping surface 36 of the first bending tool 32 canbe utilized to provide the compression area 42 with an outline of anirregular shape. The shaping surface 36 can be also be utilized to formthe first portion 48 in a first edge portion 54 and the second portion50 in a second edge portion 56 or the first portion 48 and the secondportion 50 in a first edge portion 54.

In certain embodiments, like the ones illustrated in FIGS. 2 and 4 , theshaping surface 36 is at least partially defined by a first segment 58.In some embodiments, the shaping surface 36 of the first bending tool 32is at least partially defined by a second segment 60. The first segment58 is spaced apart from the second segment 60. In the embodimentsdescribed and illustrated, the first segment 58 will be described anddepicted as being configured to receive the trailing edge portion of thefirst glass sheet 10. However, it should be appreciated that the firstsegment 58 could refer to a segment that is configured to receive theleading edge portion of the first glass sheet 10 or a pillar edgeportion of the first glass sheet 10. Once a particular edge portion ofthe first glass sheet 10 is received, the first segment 58 is configuredto support the edge portion of the first glass sheet 10. Preferably, theportion of the shaping surface 36 defined by the first segment 58 isformed in a unitary manner. Additionally, in certain embodiments, thesecond segment 60 will be described and depicted as being configured toreceive the leading edge portion of the first glass sheet 10. However,it should be appreciated that the second segment 60 could be configuredto receive the trailing edge portion of the first glass sheet 10 or apillar edge portion of the first glass sheet 10. Once a particular edgeportion of the first glass sheet 10 is received, the second segment 60is configured to support the edge portion of the first glass sheet 10.Preferably, the portion of the shaping surface 36 defined by the secondsegment 60 is formed in a unitary manner.

Positioned at one end of the first segment 58 and the second segment 60is a third segment 62. More particularly, a first end of the thirdsegment 62 is spaced apart from a first end of the first segment 58 anda second end of the third segment 62 is spaced apart from a first end ofthe second segment 60. When provided, the third segment 62 at leastpartially defines the shaping surface 36 of the first bending tool 32.Preferably, the portion of the shaping surface 36 defined by the firstsegment 98 is formed in a unitary manner. In certain embodiments, thethird segment 62 is configured to receive a pillar edge portion of thefirst glass sheet 10. In these embodiments, once a particular edgeportion of the first glass sheet 10 is received, the third segment 62 isconfigured to support the edge portion of the first glass sheet 10.

Positioned at another end of the first segment 58 and the second segment60 is a fourth segment 64. More particularly, a first end of the fourthsegment 64 is spaced apart from a second end of the first segment 58 anda second end of the fourth segment 64 is spaced apart from a second endof the second segment 60. When provided, the fourth segment 64 at leastpartially defines the shaping surface 36 of the first bending tool 32.Preferably, the portion of the shaping surface 36 defined by the fourthsegment 64 is formed in a unitary manner. In certain embodiments, thefourth segment 64 is configured to receive a pillar edge portion of thefirst glass sheet 10. In these embodiments, once a particular edgeportion of the first glass sheet 10 is received, the fourth segment 64is configured to support the edge portion of the glass sheet 10.

As illustrated in FIGS. 2 and 4 , when provided, the first segment,second segment, third segment, and fourth segment may each define adiscrete portion of the shaping surface 36 of the first bending tool 32.When the first glass sheet 10 is supported on the shaping surface 36,the first glass sheet 10 is disposed over the first segment 58, secondsegment 60, third segment 62, and fourth segment 64. A portion of thecompression area 42 may be formed over each segment 58-64. For example,in an embodiment, the first portion 48 of the compression area 42 may beformed over the first segment 58. In these embodiments, the secondportion 36 of the compression area 42 may be formed over the firstsegment 58, the second segment 60, or another segment 62, 64.

In combination, the segments 58-64 may define the generally rectangularoutline. In certain embodiments, the first segment 58, second segment60, third segment 62, and fourth segment 64 are configured as a ringwhich supports the first glass sheet 10 in a peripheral region thereof.However, the shaping surface 36 may have other configurations. Forexample, in an embodiment, the first segment 58 may not be provided in aparallel relationship with the second segment 60. In other embodiments,the third segment 62 may not be provided in a parallel relationship withthe fourth segment 64. In still other embodiments, the outline of theshaping surface 36 may be trapezoidal or have other forms suitablyconfigured to support the particular glass sheet to be shaped. Also, asis illustrated in FIG. 2 , one or more of the segments 58-64 maycomprise one or more curved portions.

The position of a segment 58-64 is regulated in a vertical direction byincreasing or decreasing the length of the one or more supports 66 thatare attached to the segment 58-64. As illustrated best in FIG. 2 , eachsupport 66 is attached to a particular segment 58-64 and, on an oppositeend, each support 66 is attached to a base member 68. On an end, eachbase member 68 is attached to a support 66 and, on an opposite end, eachbase member 68 is attached to a frame 70.

It should also be noted that FIG. 1 illustrates a direction of glasstravel with respect to the first bending tool 32 and the shaping surface36. In some embodiments, the first bending tool 32 is oriented so thatthe direction of glass travel has the trailing edge portion of the firstglass sheet 10 being received by the first segment 58. It should beappreciated that the first bending tool 32 and the shaping surface 36could be oriented in another manner with respect to the direction ofglass travel so that the trailing edge portion of the glass sheet 10 isreceived by another segment 60-64. For example, in another embodiment(not depicted), first bending tool may be oriented at 180 degrees withrespect to the embodiment described above. In this embodiment, the firstbending tool is oriented with respect to the direction of glass travelso that the second segment receives the trailing edge portion of thefirst glass sheet.

With reference to FIGS. 3-3A, which each illustrate a portion of thefirst segment 58, each segment 58-64 may be in mechanical communicationwith one or more heating elements 72. The one or more heating elements72 are utilized to heat the segment 58-64 prior the shaping the firstglass sheet 10. Two heating elements 72 may be in mechanicalcommunication with a particular segment 58-64.

Also, each segment 58-64 may comprise a protective cover 74. Theprotective cover 74 separates a support member 76 of each segment 58-64from the first glass sheet 10 and makes shaping contact with the firstglass sheet 10 when the first glass sheet 10 is being shaped.Preferably, the protective cover 74 comprises a cloth made of, forexample, stainless steel, fiber glass, poly-phenyleneterephthalamidefibers (e.g. Kevlar™), materials blended Kevlar™ polybenzoxale (PBO)fibers containing graphite (e.g. Zylon™), or various weaves of thesefibers.

Each segment 58-64 has a width. As illustrated, the width of aparticular segment is measured normal to an outer edge of the segment toan inner edge of the segment. In some embodiments, like the oneillustrated in FIG. 2 , the first segment 58 may be configured to have awidth which is greater than the width of the second segment 60. Inanother embodiment, the first segment 58 has a width which is greaterthan the width of the remaining segments 62, 64. For example, the firstsegment 58 may have a width which is more than double the width of oneor more of the second segment 60, third segment 62, and fourth segment64. In another embodiment (not depicted), two or more segments such as,for example, the first segment and the second segment or the thirdsegment may each have a width which is greater than a width of one ormore of the remaining segments such as, for example, the fourth segment.In these embodiments, the first portion 48 and the second portion 50 ofthe compression area 42 may be formed over different segments such as,for example, the first segment 58 and the second segment 60. In otherembodiments, the first portion 48 and the second portion 50 of thecompression area 42 are formed over a single segment such as, forexample, the first segment 58. In this embodiment, the first segment 58,which is illustrated in FIG. 4 , comprises a first width W_(FS1) and asecond width W_(FS2) and the first width W_(FS1) is greater than thesecond width W_(FS2).

With reference back to FIG. 3 , each segment 58-64 may be of a widthwhich allows the first glass sheet 10 to be deposited on the firstbending tool 32 and provides a space 78 between the peripheral edge 20of the first glass sheet 10 and the outer edge 80 of each segment 58-64.For example, when the first portion 48 of the compression area 42 isformed over the first segment 58, the width W_(FS) of the first segment58 may be greater than the width W₁ of the first portion 48 of thecompression area 42. Preferably, each space 78 between the peripheraledge 20 of the first glass sheet 10 and the outer edge 80 of eachsegment 58-64 is equal to the other spaces. In some embodiments, thespace 78 between the peripheral edge 20 of the first glass sheet 10 andthe outer edge 80 of each segment 58-64 may be 1.5-13 mm. In otherembodiments, the space 78 between the peripheral edge 20 of the firstglass sheet 10 and the outer edge 80 of each segment 58-64 may be3.0-6.5 mm. Advantageously, providing a space 78 between the peripheraledge 20 of the first glass sheet 10 and the outer edge 80 of eachsegment 58-64 allows for tolerance in depositing the first glass sheet10 on the first bending tool 32.

It should also be noted that the width of each segment 58-64 may begreater than the width of the portion of the compression area 42 formedover the segment 58-64. For example, when the first portion 48 of thecompression area 42 is formed over the first segment 58, which isillustrated best in FIGS. 3 and 3A, the width W_(FS) of the firstsegment 58 is greater than the width W₁ of the first portion 48 of thecompression area 42. In other embodiments, when, for example, the firstportion 48 of the compression area 42 is formed over the first segment58 and the second portion 50 of the compression area 42 is also formedover the first segment 58, a first width W_(FS1) of the first segment 58may be greater than the width W₁ of the first portion 48 of thecompression area 42 and a second width W_(FS2) of the first segment 58may be greater than the width W₂ of the second portion 36 of thecompression area 42.

From the outer edge 80, an outer portion 82 of each segment 58-64extends inward to an inner portion 84. The inner portion 84 extends fromthe outer portion 82 to an inner edge 86. In certain embodiments, likethe one illustrated in FIG. 3A, the inner portion 84 gradually reducesin thickness toward the inner edge 86. In these embodiments, a space 88separates the portion 40 of the first glass sheet 10 where thetransition 46 is formed and the first bending tool 32. It should also benoted that, in the embodiment illustrated in FIG. 3A, the first portion48 of the compression area 42 is formed over the outer portion 82 of thesegment 58 and the transition 46 is formed over the inner portion 84 ofthe segment 58.

In other embodiments, like the one illustrated in FIG. 3 , an inner end92 of the first portion 48 of the compression area 42 is formed adjacentthe inner edge 86 of a segment such as, for example, the first segment58. In this embodiment, the inner end 92 of the first portion 48 of thecompression area 42 is formed over the inner edge 86 of the firstsegment 58. More particularly, in this embodiment, the inner end 92 ofthe first portion 48 of the compression area 42 may be aligned with theinner edge 86 of the first segment 58. Further, in this embodiment, thetransition 46 is formed in a portion 40 of the first glass sheet 10which is located inward of the inner edge 86 of the first segment 58.

As illustrated in FIGS. 3 and 3A, the transition 46 between thecompression area 42 and the tension area 44 is formed in the first glasssheet 10 inward of an inner edge 94 of the shaping surface 36.Preferably, the transition 46 is formed in the portion 40 of the firstglass sheet 10 which is immediately inward of the inner edge 94 of theshaping surface 36 of the first bending tool 32. In these embodiments,each segment such as, for example, the first segment 58 is configured tosupport an edge portion of the first glass sheet 10 and an inner end ofthe edge portion is aligned with the inner edge 94 of the shapingsurface 36 of the first bending tool 32.

Referring back to FIG. 1 , the bending station 28 includes the firstbending tool 32 and, in certain embodiments, the second bending tool 96.After the glass sheet 10 is deposited on the first bending tool 32, thefirst major surface 14 of the glass sheet 10 faces the shaping surface36 of the first bending tool 32 as is illustrated in FIGS. 3 and 3A.When a second bending tool 96 is provided, the second major surface 16of the glass sheet 10 faces the shaping surface 98 of the second bendingtool 96.

When the first glass sheet 10 is shaped by press bending, the secondbending tool 96 may move toward the first glass sheet 10 prior tobending. After the first glass sheet 10 has been shaped, the secondbending tool 96 is moved away from the first glass sheet 10. If thefirst glass sheet 10 is to be press bent, once the first glass sheet 10is deposited on the shaping surface 36, the first bending tool 32 andthe second bending tool 96 begin moving towards one another to pressbend the first glass sheet 10. Following movement of the first bendingtool 32 and the second bending tool 96, the first glass sheet 10 ispress bent between the bending tools 32, 96. Also, in certainembodiments, the first bending tool 32 may move towards the secondbending tool 96, with the second bending tool 96 not moving.

The second bending tool 96 may be a male tool. In an embodiment, thesecond bending tool 96 is and full-face mold. In these embodiments, thesecond bending tool 96 may comprise a convex shaping surface. Contactbetween the edge portion 18 of the first glass sheet 10 and the secondbending tool 96 also cools the edge portion 18 to form the compressionarea 42 therein. In certain embodiments, it is preferred that theportions 48, 50 of the compression area 42 are formed in the edgeportion 18 of the first glass sheet 10 when the first glass sheet 10 issimultaneously in contact with both the first bending tool 32 and thesecond bending tool 96.

During pressing, a vacuum may be drawn on passages 100 formed in thesecond bending tool 96 to facilitate forming the first glass sheet 10into a desired shape. To assist the second bending tool 96 in holdingthe first glass sheet 10, an insulation structure (not depicted) may bedisposed near the shaping surface 36 of the first bending tool 32. Moreparticularly, the insulation structure may be disposed near the portion102 of the shaping surface 36 defined by the first segment 58 and theportions 104-108 of the shaping surface 36 defined by one or moreadditional segments 60-64. The insulation structure helps to preventheat loss from certain portions of the first glass sheet 10 adjacent theedge portion 18 of the first glass sheet 10. In certain embodiments, theinsulation structure is disposed adjacent the first glass sheet 10 wherecertain portions of the tension area 44 are formed. Preventing heat lossfrom these portions of the first glass sheet 10 allows for the vacuum toprovide a suitable holding force for forming the first glass sheet 10into a desired shape.

The position of the passages 100 can be determined by the configurationof the second bending tool 96 and the geometry of the first glass sheet10. Upon completion of shaping, the first glass sheet 10 may be releasedfrom the second bending tool 96 by way of positive pressure beingapplied through the passages 100. It can be appreciated that the bendingstation 28 may comprise more than the bending tools 32, 96 illustrated,may be oriented in a position other than the positions shown in FIG. 1 ,and have bending tools that are stationary. Upon completion of thebending process, a conveying device (not shown) serves to transport thefirst glass sheet 10 into a lehr 110. In the lehr 110, the first glasssheet 10 may be tempered or annealed as known in the art and cooled to atemperature at which handling can occur.

After being removed from the lehr 100, the first glass sheet 10 may beused in the construction of a glass article 200. The glass article 200may be utilized as a portion of a window assembly such as, for example,a windshield for a vehicle. However, the glass article 200 may haveother vehicular applications. For example, the glass article 200 may beutilized to form a side window, sunroof, or a rear window. Such a windowassembly may be monolithic or laminated. The window assembly may beinstalled in any appropriate body opening of a vehicle. It should beunderstood by one of ordinary skill in the art that the glass article200 described herein may have applications to on-highway and off-highwayvehicles. Furthermore, it would be understood by one of ordinary skillin the art that the glass article 200 may have architectural,electronic, industrial, locomotive, naval, aerospace, and otherapplications.

Embodiments of the compression area 42, tension area 44, and transition46 between compression area 42 and the tension area 44 formed in thefirst glass sheet 10 will now be described with references to the glassarticles 200 illustrated in FIGS. 5-9 .

In certain embodiments, like the ones illustrated in FIGS. 5 and 9 ,where the edge portion 18 comprises a first edge portion 54 and a secondedge portion 56, the first portion 48 may be formed in the first edgeportion 54 and the second portion 50 may be formed in the second edgeportion 56. In the embodiment illustrated in FIG. 5 , the first edgeportion 54 may have been the trailing edge portion and the second edgeportion 56 may have been the leading edge portion. In this embodiment,the first portion 48 is in a spaced apart relationship with the secondportion 50. In other embodiments, like those illustrated in FIGS. 7-8 ,when the edge portion 18 comprises a first edge portion 54, the firstportion 48 and the second portion 50 may each be formed in the firstedge portion 54. In still other embodiments, the first portion 48 may beadjacent the second portion 50. For example, as illustrated in FIGS. 7-8, when the first portion 48 and the second portion 50 are each formed inthe same edge portion, the first portion 48 may be adjacent the secondportion 50. Alternatively, the first portion 48 may be adjacent thesecond portion 50 when the first portion 48 is formed in the first edgeportion 54 and the second portion 50 is formed in the second edgeportion 56 as is illustrated in FIG. 9 . In this embodiment, the firstedge portion 54 may have been the leading edge portion or the trailingedge portion and the second edge portion 56 may have been a pillar edgeportion. In another embodiment (not depicted), the first edge portionmay have been a pillar edge portion and the second edge portion may havebeen the leading edge portion or the trailing edge portion.

As illustrated in FIG. 9 , when the first portion 48 is formed in afirst edge portion 54 and the second portion 50 is formed in a secondedge portion 56, the first portion 48 of may extend in a Y directionfrom a portion 112 of the peripheral edge 20 of the first glass sheet 10to the second portion 50. Also, and with reference back to theembodiment illustrated in FIG. 7 , when the first portion 48 and thesecond portion 50 are each be formed in a first edge portion 54, thefirst portion 48 may extend in an X direction from another portion 114of the peripheral edge 20 of the first glass sheet 10 to the secondportion 50. In these embodiments, a transition 116 from the firstportion 48 to the second portion 50 may be sharply defined.

With reference to FIG. 7 , the width W₁ of the first portion 48 may beconstant in an X direction toward a first end 118 of the first portion48 or toward a second end 120 of the first portion 48. Alternatively, incertain embodiments like the one illustrated in FIG. 8 , the width W₁ ofthe first portion 48 may gradually increase in an X direction toward thefirst end 118 or the second end 120 of the first portion 48. In theembodiments described above and as illustrated in FIG. 7 , the width W₂of the second portion 50 may be constant in a direction toward a firstend 122 of the second portion 50. In certain embodiments, the width W₂of the second portion 50 may be constant from the first end 122 to asecond end 124 of the second portion 50.

The tension area 44 is surrounded by the compression area 42. Thetension area 44 is formed in a second portion 38 of the first glasssheet 10. The second portion 38 of the first glass sheet 10 is locatedinward of the edge portion 18 of the first glass sheet 10. Thus, thetension area 44 is provided inward of the compression area 42.

As noted above, the transition 46 is provided between the compressionarea 42 and the tension area 44. The transition 46 is formed in a thirdportion 40 of the first glass sheet 10. The third portion 40 of thefirst glass sheet 10 is positioned between the edge portion 18 of thefirst glass sheet 10 and the second portion 38 of the first glass sheet10. The third portion 40 of the first glass sheet 10 is adjacent theedge portion 18 of the first glass sheet 10. In this location, thecompression area 42 surrounds the transition 46. The third portion 40 ofthe first glass sheet 10 is also adjacent the second portion 38 of thefirst glass sheet 10. In this location, the transition 46 surrounds thetension area 44.

In certain embodiments, the transition 46 comprises a first portion 126.The first portion 126 extends from the edge portion 18 of the firstglass sheet 10. The first portion 126 may extend from the edge portion18 of the first glass sheet 10 in an X direction and/or Y direction. Thetransition 46 may also comprise a second portion 128. The second portion128 may be provided in a parallel relationship with the first portion126. In some embodiments, the second portion 128 extends from the edgeportion 18 of the first glass sheet 10 in an X direction and/or Ydirection.

Further, the transition 46 may comprise a third portion 130. The thirdportion 130 may connect the first portion 126 to the second portion 128.When the third portion 130 connects the first portion 126 to the secondportion 128, the third portion 130 may be provided in a perpendicularrelationship with the first portion 126 and the second portion 128. Inother embodiments, the third portion 130 may connect the first portion126 to the second portion 128 and be provided in an oblique relationshipwith the first portion 126 and the second portion 128. In embodimentswhere the third portion 130 connects the first portion 126 to the secondportion 128, the third portion 130 may extend in a Y direction. As isillustrated in FIG. 5 , the third portion 130 may extend in a Ydirection from an edge portion 18 of the first glass sheet 10.Alternatively, as is illustrated in FIG. 7 , the third portion 130 mayextend in a Y direction from the first portion 126 to the second portion128 or vice versa.

As illustrated in, for example, FIG. 7 , the transition 46 may comprisea linear portion. In this embodiment, the first portion 126, secondportion 128, and third portion 130 may be linear. In other embodiments,like the one illustrated in FIG. 8 , the transition 46 may comprise acurved portion such as, for example, the first portion 126. Asillustrated in FIG. 5 , a junction 132 connecting the first portion 126and the third portion 130 may be sharply defined. In other embodiments,like the one illustrated in FIG. 7 , a junction 132 connecting theportions of the transition 46 may be curved. Also, the junctionconnecting the second portion 128 and the third portion 130 may besharply defined or, in other embodiments (not depicted), the junctionconnecting the second portion 128 and the third portion 130 may becurved.

Under certain conditions, it is desirable to increase the width of aportion of the compression area 42. For example, when it is desired toprovide an electrical component such as, for example, a terminalconnector in mechanical communication with the first glass sheet 10 viaa solder process or another method, it may be desirable to increase thewidth of a portion of the compression area 42. When the width is notincreased, the electrical component may be positioned directly over thetension area 44, transition 46, or another portion of the first glasssheet 10 that has tensile area stress. Providing the electricalcomponent in mechanical communication with the first glass sheet 10 overthe tension area 44, transition 46 or another portion of the first glasssheet 10 that has tensile area stress may result in weakening andfailure of the first glass sheet 10. Advantageously, the embodimentsdescribed herein allow the width of a portion of the compression area 42to be increased so that the other portions of the first glass sheet 10that have tensile area stress are provided in a predetermined location.For example, the width of a portion of the compression area 42 can beincreased by utilizing an appropriately configured bending tool 32, 96so that the location of the transition 46, the tension area 44, andother portions of the first glass sheet 10 that have tensile area stressare inward of the position of the electrical component.

When it is desired to utilize the glass article 200 as a windshield, thefirst glass sheet 10 may be laminated to a second glass sheet 12 to formthe glass article 200. The first glass sheet 10 and the second glasssheet 12 may be similarly configured and utilized in the method insimilar manners. It should be appreciated that the properties describedin relation to the first glass sheet 10 could also be exhibited by thesecond glass sheet 12. However, in certain embodiments, the first glasssheet 10 and the second glass sheet 12 may have different configurationsor be utilized in the method in different manners.

When the first glass sheet 10 is to be laminated to a second glass sheet12, a polymeric interlayer 202 is provided between the first glass sheet10 and the second glass sheet 12. As illustrated best in, for example,FIG. 6 , the first glass sheet 10 is depicted as the inner pane of glassand the second glass sheet 12 is depicted as the outer pane of glass.However, it should be appreciated that, in other embodiments, the firstglass sheet 10 may be the outer pane of glass and the second glass sheet12 may be the inner pane of glass.

Preferably, the polymeric interlayer 202 is clear and substantiallytransparent to visible light. Optionally, the polymeric interlayer 202can be tinted and/or comprise an IR reflective film to provideadditional solar control features. The polymeric interlayer 202 is of orincludes a suitable polymer such as, for example, polyvinyl butyral(PVB) or another polymer. In certain embodiments like those shown inFIG. 6 , the polymeric interlayer 202 is provided as a sheet of materialin a shape substantially matched to that of the first glass sheet 10 andthe second glass sheet 12. In other embodiments (not depicted), thepolymeric interlayer is provided in a shape substantially matched tothat of the first glass sheet or the second glass sheet.

The polymeric interlayer 202 may be of any suitable thickness. Incertain embodiments, the polymeric interlayer 202 has a thickness ofbetween 0.5 and 1.6 mm. Preferably, the polymeric interlayer 202 has athickness of between 0.6 and 0.9 mm. In these embodiments, a typicalthickness of the polymeric interlayer 26 is 0.76 mm.

To form the glass article 200, the first glass sheet 10 and the secondglass sheet 12 may be laminated to each other or are otherwise adheredtogether via the polymeric interlayer 202. Lamination processes known inthe art are suitable for adhering the first glass sheet 10 to the secondglass sheet 12 via the polymeric interlayer 202 and forming the glassarticle 200. Generally, such lamination processes will include providingthe polymeric interlayer 202 between the first glass sheet 10 and thesecond glass sheet 12 and subjecting the polymeric interlayer 202 andglass sheets 10, 12 to a predetermined temperature and pressure tocreate a glass article 200 that is laminated.

Referring back to FIGS. 5 and 7-9 , under certain conditions, it may bedesirable to heat a portion 204 of the glass article 200 where, forexample, wipers rest. Heating this portion 204 of the glass article 200can prevent the wipers from freezing thereto when the wipers are atrest. The aforementioned portion 204 of the window assembly may alsoreferred to hereinafter as the “wiper rest area.” Heating of the wiperrest area 204 can be accomplished by any suitable method. In anembodiment, the wiper rest area 204 is heated by electrical resistanceheating.

Electrical resistance heating can be accomplished by providing power tothe first glass sheet 10 via an electrical component such as, forexample, a terminal connector 206, 206A. The terminal connector 206 maybe provided as a portion of a wire assembly 208. Such a wire assembly208 may be utilized to communicate power from a power supply (notdepicted) through a conductive wire 210 to the terminal connector 206,206A. The wire assembly 208 may comprise a plurality of terminalconnectors 206, 206A. However, in describing the embodiments of theglass article 200, only one terminal connector 206, which is inmechanical communication with the first glass sheet 10, will bedescribed below. It should be appreciated that the glass article 200 maycomprise two or more terminal connectors 206, 206A in mechanicalcommunication with the first glass sheet 10. For example, as illustratedbest in FIG. 5A, a first terminal connector 206 and a second terminalconnector 206A may be in mechanical communication with the first glasssheet 10. As illustrated, the second terminal connector 206A is in aspaced apart relationship with the first terminal connector 206. Inpractice, it is preferred that a terminal connector 206, 206A isprovided for each busbar 212, 212A provided on the first glass sheet 10.

The first terminal connector 206 is in a spaced apart and parallelrelationship with a portion 214 of the peripheral edge 20 of the firstglass sheet 10. The first terminal connector 206 is attached to a busbar212. Preferably, the first terminal connector 206 is attached to thebusbar 212 via solder 216, which is illustrated in FIG. 6 . Also, thefirst terminal connector 206 is in electrical communication with thebusbar 212 via the solder 216. Power may be communicated from the powersupply through the wire assembly 208, via the conductive wire 210 andthe first terminal connector 206, to the busbar 212. From the busbar212, power is communicated to conductive traces 218 adjacent the wiperrest area 204 to heat the wiper rest area 204 to a desired temperature.The busbar 212 and conductive traces 218 can be formed on either thefirst major surface 14 or the second major surface 16 of the first glasssheet 10. In the embodiment illustrated in FIGS. 5-6 , the busbar 212and conductive traces 218 are formed on the first major surface 14.Preferably, the busbar 212 and conductive traces 218 are formed on thefirst glass sheet 10 prior to the first glass sheet 10 being shaped. Thebusbar 212 and conductive traces 218 may be formed by conventionalprocesses such as deletion, sputtering or silk-screening processes orthe like.

Also, as shown in FIG. 6 , a potting layer 220 is disposed over thefirst major surface 14 of the first glass sheet 10. In certainembodiments, the potting layer 220 may be provided over at least eachterminal connector 206, 206A, a portion of each busbar 212, 212, and aportion of each conductive wire 210. The potting layer 220 is of athickness which allows a portion of the potting layer 220 to be disposedover each terminal connector 206, 206A. The potting layer 220 protectsthe terminal connectors 206, 206A from environmental damage andelectrically insulates the terminal connectors 206, 206A. Suitablepotting layer materials include acrylics, silicones and urethanes.However, other potting layer materials are suitable for use in formingthe window assembly. It should be appreciated that in certainembodiments (not depicted), like, for example, when the glass article isutilized to close a side or rear opening of the vehicle, a potting layermay not be utilized.

A retaining member 222 may be utilized to prevent the potting layermaterial from flowing out of the area where it is desired after it isdisposed over the first glass sheet 10 and before it hardens. In orderto form the glass article 200, the retaining member 22 is disposed onthe first major surface 14 of the first glass sheet 10. In theseembodiments, the retaining member 22 may be attached to the first majorsurface 14 via an adhesive or another method. Preferably, the retainingmember 222 is configured to be disposed around each terminal connector206, 206A provided. Once the potting layer material has been providedover each terminal connector 206, 206A, the potting layer material iscontained by the retaining member 222. After the potting materialhardens, the retaining member 222 may in remain in place such that theretaining member 222 is disposed around the potting layer 220 or may beremoved from the first major surface 14 of the first glass sheet 10 andreused.

As noted above, the first terminal connector 206 is attached to andelectrical communication with the busbar 212 via solder 216. Soldercompositions known in the art are suitable for use in forming the glassarticle 200. In certain embodiments, the solder 216 may comprise lead.In other embodiments, the solder 216 is lead-free, i.e. contains nolead. In embodiments where solder is of the lead-free variety, thesolder 216 may comprise indium, tin, silver, copper, zinc, bismuth, andmixtures thereof. In certain embodiments where solder is of thelead-free variety, the solder 216 comprises more indium than any othermetal component in the solder. In one such embodiment, the solder 216comprises 65% indium, 30% tin, 4.5% silver, and 0.5% copper. In otherembodiments where the solder 216 is of the lead-free variety, anothercomposition may be utilized.

Prior to soldering, the first terminal connector 206 is positioned overa portion of the busbar 212. The portion of the busbar 212 is locatedover the first portion 48 of the compression area 42. Thus, the firstterminal connector 206 is positioned over the first portion 48 of thecompression area 42. After positioning, the first terminal connector 206is attached to the busbar 212 via soldering, or another suitable method,over the first portion 48 of the compression area 42, which is outwardfrom a portion of the tension area 44, the transition 46 and other areasof the first glass sheet 10 having certain tensile area stress. Also, itshould be noted that the entire busbar 212 and the conductive traces 218may be provided over the compression area 42. Providing the entirebusbar 212 and the conductive traces 218 over the compression area 42may also help to maintain the strength and ensure the integrity of thefirst glass sheet 10.

The glass article 200 may be formed using a soldering method known inthe art. However, in certain embodiments, it is preferred that the glassarticle 200 is formed utilizing a resistance soldering method. Moreparticularly, the first terminal connector 206 may be provided inmechanical communication with the first glass sheet 10 via resistancesoldering. Utilizing resistance soldering allows the solder 216 to beheated to a temperature above its melting point, which enables thesolder 216 to attach the first terminal connector 206 to the busbar 212.Due heating the solder 216, if the first terminal connector 206 isattached to the busbar 212 in a location which is over the tension area44, transition 46, or another undesirable portion of the first glasssheet 10 having tensile area stress, then the glass article 200 mayexhibit breakage such as spalling. Advantageously, the embodimentsdescribed herein help to prevent and eliminate glass breakage andspalling by ensuring that the electrical connector 206, 206A ispositioned over the compression area 42.

From the foregoing detailed description, it will be apparent thatvarious modifications, additions, and other alternative embodiments arepossible without departing from the true scope and spirit. Theembodiments discussed herein were chosen and described to provide thebest illustration of the principles of the invention and its practicalapplication to thereby enable one of ordinary skill in the art to usethe invention in various embodiments and with various modifications asare suited to the particular use contemplated. As should be appreciated,all such modifications and variations are within the scope of theinvention.

1. A glass article, comprising: a first glass sheet comprising acompression area and a tension area formed in the first glass sheet,wherein the compression area exhibits a compressive area stress of20-100 MPa and is formed in an edge portion of the first glass sheet,the compression area comprising a first portion and a second portion,the first portion having a width (W₁) which is greater than a width (W₂)of a second portion.
 2. The glass article of claim 1, wherein thetension area is formed in a second portion of the first glass sheet, thesecond portion of the first glass sheet is located inward of the edgeportion of the first glass sheet, and a transition is formed in thefirst glass sheet in a third portion of the first glass sheet.
 3. Theglass article of claim 1, further comprising a first terminal connectorpositioned over the first portion of the compression area and inmechanical communication with the first glass sheet.
 4. The glassarticle of claim 1, wherein a transition in the first glass sheet isinward of a first terminal connector in mechanical communication withthe first glass sheet.
 5. The glass article of claim 1, wherein the edgeportion of the first glass sheet comprises a first edge portion and asecond edge portion, the first portion of the compression area beingformed in the first edge portion and the second portion of thecompression area being formed in the second edge portion.
 6. The glassarticle of claim 1, wherein a transition in the first glass sheetcomprises a first portion, the first portion extending from the edgeportion of the first glass sheet, a second portion provided in aparallel relationship with the first portion, the second portionextending from the edge portion of the first glass sheet, and a thirdportion connecting the first portion to the second portion.
 7. The glassarticle of claim 1, wherein the edge portion of the first glass sheetcomprises a first edge portion, the first portion of the compressionarea and the second portion of the compression area being formed in thefirst edge portion.
 8. The glass article of claim 1, wherein atransition in the first glass sheet exhibits an area stress of 0 MPa andthe tension area exhibits a tensile area stress of less than 8 MPa. 9.The glass article of claim 1, further comprising a polymeric interlayerprovided between the first glass sheet and a second glass sheet; orwherein the first glass sheet is shaped.
 10. The glass article of claim4, further comprising a second terminal connector which is in a spacedapart relationship with the first terminal connector; or wherein thefirst terminal connector is in a spaced apart and parallel relationshipwith a portion of a peripheral edge of the first glass sheet.
 11. Theglass article of claim 5, wherein the first portion of the compressionarea is in a spaced apart relationship with the second portion of thecompression area.
 12. The glass article of claim 5, wherein the firstportion of the compression area is adjacent the second portion of thecompression area.
 13. The glass article of claim 5, wherein the firstportion of the compression area extends from a peripheral edge of thefirst glass sheet to the second portion of the compression area.
 14. Theglass article of claim 5, wherein a transition from the first portion ofthe compression area to the second portion of the compression area issharply defined.
 15. The glass article of claim 5, wherein a transitionin the first glass sheet comprises a curved portion.
 16. The glassarticle of claim 5, wherein a transition in the first glass sheetcomprises a linear portion.
 17. The glass article of claim 6, whereinthe third portion is provided in a perpendicular relationship with thefirst portion and the second portion.
 18. The glass article of claim 7,wherein the width (W₁) of the first portion gradually increases in adirection toward a first end of the first portion.
 19. The glass articleof claim 1, wherein the first glass sheet is shaped and the shaped firstglass sheet is flat or bent.
 20. The glass article of claim 1, whereinin the first glass sheet a transition is located between the compressionarea and the tension area.